Test drivers drive, evaluate, and grade new automobiles and other vehicles before they are made available for sale to the public. They spend many hours driving their assigned model in various driving situations, climates, and speeds. As members of a new product development team, test drivers make suggestions for specific alterations to the car's design, function, and performance. Test drivers are employed by auto manufacturers worldwide, though some may work for contractors specializing in automotive testing or development. Others work as automobile writers and reviewers for trade publications.